Level Scheme Research Articles

Experimental study of the S38 excited level scheme

Information on the $^{38}\mathrm{S}$ level scheme was expanded through experimental work utilizing a fusion-evaporation reaction and in-beam $\ensuremath{\gamma}$-ray spectroscopy. Prompt $\ensuremath{\gamma}$-ray transitions were detected by the Gamma-Ray Energy Tracking Array (GRETINA) and recoiling $^{38}\mathrm{S}$ residues were selected by the Fragment Mass Analyzer (FMA). Tools based on machine-learning techniques were developed and deployed for the first time in order to enhance the unique selection of $^{38}\mathrm{S}$ residues and identify any associated $\ensuremath{\gamma}$-ray transitions. The new level information, including the extension of the even-spin yrast sequence through ${J}^{\ensuremath{\pi}}={8}^{(+)}$, was interpreted in terms of a basic single-particle picture as well shell-model calculations which incorporated the empirically derived FSU interaction. A comparison between the properties of the yrast states in the even-$Z, N=22$ isotones from $Z=14$ to 20, and for $^{36}\mathrm{Si}--^{38}\mathrm{S}$ in particular, was also presented with an emphasis on the role and influence of the neutron $1{p}_{3/2}$ orbital on the structure in the region.

SIPAM-4 scheme improves bit error rate performance in MISO X-ray communication system

X-ray communication (XCOM) technology, which uses X-ray as the carrier wave, is expected to solve the problem of reentry blackout region communication with its good penetration characteristics. In order to mitigate the effects of non-linear distortion of the gated X-ray tube (GMXT), the multiple-input single-output (MISO) technique has been introduced in XCOM systems. A pulse amplitude modulation scheme based on superimposed intensity (SIPAM) was proposed and achieved by configuring GMXTs with on/off keying modulation in MISO XCOM system. The feasibility of the proposed SIPAM scheme in XCOM was numerically investigated through Monte Carlo simulations. As the divergence angle of the GMXT increases, the optical power distribution tends to be more uniform in the receiving plane. It can greatly relax the requirements for link alignment. After that, we conduct a proof-of-concept experiment for the SIPAM with four levels (SIPAM-4) scheme by employing two GMXTs and an LYSO-SiPM-based X-ray detector. The experimental results show that when the bit error rate is within the forward error correction limit of 3.8 × 10−3, the SIPAM-4 scheme can reach a maximum communication rate of 1.20 Mbps, which is 20% higher than the conventional PAM-4 scheme. It can be included that the proposed MISO based the SIPAM-4 modulation scheme could improve the performance of the X-ray communication system.

Measuring the performance of higher education among state universities and colleges in SOX Region, Philippines

As state universities and colleges (SUCs) in the Philippines are confronted by tough competition for limited resources, and to show to government legislators that subsidy on tertiary education meaningfully produces significant returns; thus, they are pressed to undertake continuous improvement for optimum performance. Practically, measuring the performance of SUCs is essential to identify critical issues, make informed decisions, and enhance higher education policies. In this descriptive-evaluative study, the institutional performance was measured using the Fiscal Year 2016 SUC levelling instrument of department of budget management (DBM) and the commission on higher education (CHED), covering four key result areas (KRA): i) Relevance and quality of teaching; ii) Research productivity, iii) Community engagement; and iv) Resources management. Respondents included 217 faculty members and 24 deans from the four SUCs in SOX Region, Philippines. A combination of descriptive and inferential statistics was used in the data analysis. Results indicated that the SUCs fared randomly in the leveling scheme. SUC-Y got excellent performance, while SUC-X tailed at a very satisfactory rating in all areas. Statistical tests showed that SUC-Y was relatively superior to the other SUCs. Moreover, the performance of SUC-W and Z were comparable and found as the lowest in the group. The major issues and challenges affecting institutional performance include multi-tasking or designation of faculty to administrative positions, inadequate laboratory facilities, and limited online modality for laboratory subjects.

Study on Risk Prediction Model of Expressway Agglomerate Fog-Related Accidents

Based on meteorological observations, traffic flow data and information of traffic accidents caused by fog or agglomerate fog along the expressways in Jiangsu Province and Anhui Province in China from 2012 to 2021, key impact factors including meteorological conditions, road hidden dangers and traffic flow conditions are integrated to establish the prediction model for risk levels of expressway agglomerate fog-related accidents. This model takes the discrimination of the occurrence conditions of agglomerate fog as the starting term, and determines the hazard levels of agglomerate fog-related accidents by introducing the probability prediction value of meteorological conditions for fog-related accident as the disaster-causing factor. On this basis, the hourly road traffic flow and the location of road sections with a hidden danger of agglomerate fog are taken as traffic and road factors to construct the correction scheme for the hazard levels, and the final predicted risk level of agglomerate fog-related accident is obtained. The results show that for the criteria of disaster-causing factor classification threshold, 72.3% of fog-related accidents correspond to a hazard of a medium level or above, and 86.2% of the road traffic flow conditions are consistent with the levels of the traffic factor defined based on parametric indexes. For risk level prediction, six out of the seven agglomerate fog-related accidents correspond to the level of higher risk or above, which can help provide meteorological support for traffic safety under severe weather conditions. Moreover, the model takes into account the impacts of traffic flow and the road environment, which is conducive to further improving the reliability of the risk assessment results.

Revisiting band structures in 118Xe nucleus via in-beam γ-ray spectroscopy* *The authors are grateful for the pelletron and support staff of IUAC, New Delhi. We would also like to acknowledge the contribution of the INGA collaboration, which is partially funded by the Department of Science and Technology (DST, GoI; project no. IR/S2/PF-03/2003-I) and University Grants Commission (UGC). This work was

The neutron deficient Xe nuclei with A 120 are predicted to have strong octupole correlation at low spins. In the present study, an attempt was made to improve upon the level scheme and also to examine the signatures of octupole correlation in Xe via high spin γ-ray spectroscopy. High spin states in Xe have been populated via the Nb(Si, p2n)Xe fusion-evaporation reaction at a beam energy of 115 MeV provided by the 15 UD pelletron accelerator facility at IUAC, New Delhi. In the experiment, seven new γ-transitions have been found and placed appropriately in the level scheme. A theoretical study using the triaxial projected shell model (TPSM) approach suggests that the first bandcrossing is due to the alignment of two neutrons, and a parallel band tracking the yrast configuration is the γ-band built on the two-quasiparticle state. Enhanced E1 transition rates measured between opposite parity bands involving νh and ν d orbitals having Δj = Δl = 3 indicate the presence of octupole correlation in this nucleus.

Coexistence of single-particle and collective excitation in Ni61

The high spin states in 61 Ni have been studied using the fusion evaporation reaction, Ti( $^{14}$C,3n) $^{61}$Ni at an incident beam energy of 40 MeV. A Compton suppressed multi-HPGe detector setup, consisting of six Clover detectors and three single crystal HPGe detectors was used to detect the de-exciting $\gamma$ rays from the excited states. The level scheme has been extended up to an excitation energy of 12.8 MeV and a tentative J$_{\pi}$ = 35/2$^+$ . The low-lying negative parity levels are found to be generated by single particle excitation within the f p shell and also excitations to the g$_{9/2}$ orbitals as explained well with shell model calculations using the GXPF1Br+V M U (modified) interaction. Two rotational structure of regular E2 sequences with small to moderate axial deformation have been established at higher excitation energy. Most interestingly, two sequences of M1 transitions are reported for the first time and described as magnetic rotational bands. The shears mechanism for both the bands can be described satisfactorily by the geometrical model. The shell model calculation involving the cross shell excitation beyond the fp shell well reproduce the M1 and E2 sequences. The shell model predicted B(M1) values for the magnetic rotational band B1 show the decreasing trend with spin as expected with closing of the shears.

Broadband EPR Spectroscopy of the Ground Electron State of the Fe4+ Impurity Ion in Amethyst

Fine structure of ground electron state of Fe4+ impurity ion in a natural amethyst crystal was studied by broadband electron paramagnetic resonance spectroscopy in the frequency range of 34–500 GHz. It is established that energy levels scheme consists of ground quasi-doublet Sz = ± 2, quasi-doublet S z= ± 1 and singlet Sz=0 with zero-field energies ± 4.9 GHz, 435.2 ± 45.4 GHz and 584 GHz, respectively. Parameters of effective spin Hamiltonian describing dependences of electron spin levels on magnetic field are determined.

High-spin spectroscopy in At207 : Evidence of a 29/2+ isomeric state

Yrast and near-yrast states above the known 25/2$^{+}$ isomer in $^{207}$At are established for the first time. The level scheme is extended up to 47/2$\hbar$ and 6.5 MeV with the addition of about 60 new $\gamma$-ray transitions. The half-life of the 25/2$^{+}$ isomer is revisited and a value of $T_{1/2}$ = 107.5(9) ns is deduced. Evidence of a hitherto unobserved 29/2$^{+}$ isomer in $^{207}$At is presented. A systematic study of $B(E3)$ values for the transitions de-exciting the 29/2$^{+}$ isomer in the neighboring odd-$A$ At isotopes suggests a half-life in the 2$-$4.5 $\mu$s range for this state in $^{207}$At. The experimental results are compared with large-scale shell-model calculations performed using the KHM3Y effective interaction in the $Z$ = 50$-$126, $N$ = 82$-$184 model space and an overall good agreement is noted between the theory and the experiment. A qualitative comparison of the excited states and the isomers with analogous states in neighboring nuclei provides further insight into the structure of $^{207}$At.

Nuclear Data Sheets for A=245

Available information pertaining to the nuclear structure of ground and excited states for all known nuclei with mass numbers A=245 have been compiled and evaluated. The adopted level and decay schemes, as well as the detailed nuclear properties and configuration assignments based on experimental data, are presented for these nuclides. When there are insufficient data, expected values from systematics of nuclear properties and/or theoretical calculations are utilized. Unexpected or discrepant experimental results are also noted. Since the last evaluation, new rotational bands in 245Pu have been observed to high spin from transfer reaction 244Pu(209Bi, 208Biγ) by 2014Ho16. While in 245Am, the 249Bk α decay measurements by 2013Ah03 added a new rotational band based on π3/2[521] configuration. The 245Pu β− decay scheme is basically what was proposed in the late 60's and 47 γ rays have still not been placed. In 245Cm, precise alpha energies and intensities were measured by 2015Ah03 in 249Cf α decay. Their reported alpha energies of the main α group were about 2 keV lower than in the previous evaluation. The spin and parity of the g.s. of 245Es is still ambiguous as more detailed information on the decay is needed. With the production of 249No via fusion evaporation reaction by groups in Dubna and GSI, it's alpha decay was studied and some properties of the daughter 245Fm were published and included in this evalaution. Information on the other nuclides is scarce and not much has been investigated since the last evaluation. A summary and compilation of the discovery of the various nuclides in this mass region is given in: 2013Fr02 (245Pu, 245Am, 245Cm, 245Bk, 245Cf), 2011Me01 (245Es), and 2013Th02 (245Md, 245Fm).

A curved boundary treatment for discrete Boltzmann model of shallow water flows based on a partially saturated method

In the present study, a boundary treatment scheme named the partially saturated method (PSM) is incorporated into the discrete Boltzmann model (DBM) for shallow water flows to deal with complex curved boundaries. In this PSM-DBM, the two-dimensional 16 velocity levels scheme is adopted and the finite difference method is used to solve the governing equation. Then, the PSM-DBM has been applied to simulate four cases, i.e. such as steady flow in a bending channel, the flow past a stationary cylinder, a jet-forced flow in a circular basin and flow in a meandering channel with 90° consecutive bends. The simulated results have been compared with the experiments and the simulation by traditional numerical simulation. The study shows that the agreement between simulation and experiments is good. It is demonstrated that the PSM-DBM is stable and accurate to deal with the curved boundaries. Moreover, the implementation of the PSM is relatively straightforward in treating stationary curved geometries and is easy to be incorporated into the DBM for shallow water flows. In conclusion, the proposed PSM-DBM can be used widely for flows with curved boundaries.

Temperature effects and mechanism of IR luminescence of colloidal Ag2Se QDs passivated with 2-mercaptopropionic acid

The paper presents the new luminescence regularities of hydrophilic colloidal Ag2Se quantum dots (QDs), passivated with 2-mercaptopropionic acid molecules. It was found that an increase in the selenium precursor concentration, as well as a decrease in the sample temperature to 80 K provides the luminescence enhancement in the long-wavelength band (840-890 nm) with simultaneous strong quenching in the short-wavelength band (715-720 nm). The Stokes shift analysis suggested that the short-wavelength luminescence peak arises as a result of radiative annihilation of an exciton, while the long-wavelength one arises due to radiative recombination at trap states. An analysis of the luminescence excitation spectra at both luminescence bands, luminescence decay curves along the luminescence spectrum, and temperature dependence of the luminescence intensity made it possible to present a scheme of the energy levels and transitions that determine the luminescence regularities of colloidal Ag2Se QDs.

Level scheme study of Mo91 : Weak-coupling approximation in the N=50 region

The level scheme of $^{91}\mathrm{Mo}$ has been studied using the GALILEO $\ensuremath{\gamma}$-ray spectrometer at Laboratori Nazionali di Legnaro, INFN. Five transitions together with four levels are identified for the first time by the $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ coincidence measurement, considerably enriching the negative band in $^{91}\mathrm{Mo}$. The discrepancy in the previous parity assignments for the states higher than 3807.5 keV has been clarified with the help of new experimental results. A shell-model calculation employing the JUN45 interaction is performed in order to get a further understanding of the level structure of $^{91}\mathrm{Mo}$. Being close to $N=50$ shell closure, the weak-coupling approximation between the valence ${g}_{9/2}$ neutron-hole with the even-even core $(^{92}\mathrm{Mo})$ is discussed in $^{91}\mathrm{Mo}$.

Determination of nuclear level density based on a fully microscopic statistical partition function method for 58Ni

Nuclear level density (NLD) is calculated using the statistical partition function method for 58Ni. The microscopic recursive approach based on the realistic single particle levels schemes obtained from various nuclear potentials is used to remove various simplifying approximations and accurately determine the NLD. The effect of these approximations is determined by comparing the results of this method with the usual and common calculations of the Fermi gas model. It is shown that such a fully microscopic approach represents the NLD behavior according to the available experimental data.

First spectroscopic study of odd-odd Cu78

Nuclei in the vicinity of Ni78 are important benchmarks for nuclear structure, which can reveal changes in the shell structure far from stability. Spectroscopy of the odd-odd isotope Cu78 was performed for the first time in an experiment with the EURICA setup at the Radioactive Isotope Beam Factory at RIKEN Nishina Center. Excited states in the neutron-rich isotope were populated following the β decay of Ni78 produced by in-flight fission and separated by the BigRIPS separator. A level scheme based on the analysis of γ−γ coincidences is presented. Tentative spin and parity assignments were made when possible based on the β-decay feeding intensities and γ-decay properties of the excited states. Time correlations between β and γ decay show clear indications of an isomeric state with a half-life of 3.8(4) ms. Large-scale Monte Carlo shell-model calculations were performed using the A3DA-m interaction and a valence space comprising the full fp shell and the 1g9/2 and 2d5/2 orbitals for both protons and neutrons. The comparison of the experimental results with the shell-model calculations allows interpreting the excited states in terms of spin multiplets arising from the proton-neutron interaction. The results provide further insight into the evolution of the proton single-particle orbitals as a function of neutron number, and quantitative information about the proton-neutron interaction outside the doubly magic Ni78 core.Received 6 October 2022Revised 3 January 2023Accepted 9 January 2023DOI:https://doi.org/10.1103/PhysRevC.107.044301©2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeta decayEnergy levels & level densitiesIsomer decaysNuclear spin & parityNuclear structure & decaysNucleon-nucleon interactionsShell modelProperties59 ≤ A ≤ 89Nuclear Physics

A new insight into the mechanism of persistent luminescence phosphors SrS: Eu2+, Pr3+

The red persistent luminescence phosphors SrS: , (x = 0∼0.001, y = 0∼0.003) were synthesized by the solid-state reaction method in a weak reducing atmosphere of active carbon. The synthetic parameters, photoluminescence characteristics, and dynamic properties of thermoluminescence of the phosphors were studied systematically. According to the results of photoluminescence spectra of SrS: , , the energy level scheme of the phosphors was confirmed quantitatively. Based on the studies of the scanning electron microscope (SEM), UV-Visible absorbance spectra, afterglow decay curves, thermoluminescence(TL) spectra, and X-ray photoelectron spectroscopy (XPS) spectra, we found that the SrS: , (SSEP) phosphor presented the best persistent luminescence property, which mainly resulted from its outstanding absorbance characteristic, deeper depth of () defects, and fewer defect concentration belonging to the higher-order kinetics. Those comprehensive results deduced that a complex defect ()- should present in the Eu2+ doping phosphors, and the Pr3+ doping will produce defects, which can suppress the formation of () defects and increase their energy depth.

Crystal field excitation in the chiral helimagnet YbNi3Al9

A crystal field level scheme of a uniaxial chiral helimagnet $\mathrm{Yb}{\mathrm{Ni}}_{3}{\mathrm{Al}}_{9}$, exhibiting a chiral magnetic soliton lattice state by Cu substitution for Ni, has been determined by inelastic neutron scattering. The ground and the first excited doublets are separated by 44 K and are simply expressed as $\ensuremath{\alpha}|\ifmmode\pm\else\textpm\fi{}7/2\ensuremath{\rangle}+\ensuremath{\beta}|\ensuremath{\mp}5/2\ensuremath{\rangle}$, with $\ensuremath{\alpha}$ and $\ensuremath{\beta}$ nearly equal to $\ifmmode\pm\else\textpm\fi{}1/\sqrt{2}$. The easy axis of the crystal field anisotropy is the $c$ axis when the excited levels are populated at high temperatures and high magnetic fields. On the other hand, the magnetism at low temperatures and low magnetic fields, where only the ground doublet is populated, is described by an easy-plane anisotropy which may be treated as an $S=1/2$ system with an anisotropic $g$ factor, ${g}_{xy}=3.02$ and ${g}_{z}=1.14$. An orbital-dependent exchange interaction is also discussed to explain the temperature dependence of the magnetic susceptibility based on this level scheme.

Magnetic structure and crystal field states ofPr2Pd3Ge5:μSRand neutron scattering investigations

We present the results of muon spin relaxation ($\ensuremath{\mu}\mathrm{SR}$), neutron powder diffration (NPD), and inelastic neutron scattering (INS) investigations on polycrystalline ${\mathrm{Pr}}_{2}{\mathrm{Pd}}_{3}{\mathrm{Ge}}_{5}$. The polycrystalline ${\mathrm{Pr}}_{2}{\mathrm{Pd}}_{3}{\mathrm{Ge}}_{5}$ is known to exhibit two antiferromagnetic transitions near ${T}_{\mathrm{N}1}=8.3$ K and ${T}_{\mathrm{N}2}=7.5$ K which is confirmed by the heat capacity measurements on the present sample. In the magnetically ordered state the NPD data show clear evidence for magnetic Bragg peaks, which for $T<{T}_{\mathrm{N}2}$ could be indexed with a propagation vector k = (1, 0, 0), and with k = (1, 0, 0.07) for ${T}_{\mathrm{N}2}<T<{T}_{\mathrm{N}1}$. We have determined the magnetic structure and found a canted antiferromagnetic structure of ordered ${\mathrm{Pr}}^{3+}$ moments. At 7.6 K we find an amplitude modulated incommensurate antiferromagnetic arrangement of ordered moments with a maximum ordered moment of 1.64(3) ${\ensuremath{\mu}}_{\mathrm{B}}$/Pr lying in the $ab$ plane tilted at about ${26}^{\ensuremath{\circ}}$ from the $b$ axis. At 1.8 K the antiferromagnetic structure is found to be commensurate with an ordered moment of 2.80(6) ${\ensuremath{\mu}}_{\mathrm{B}}$/Pr lying in the $ab$ plane tilted at about ${28}^{\ensuremath{\circ}}$ from the $b$ axis. Our zero-field $\ensuremath{\mu}\mathrm{SR}$ spectra at 1.5 K and at shorter time scale (below 0.5 $\ensuremath{\mu}\mathrm{s}$) reveal two oscillatory frequencies further supporting a long-range-ordered magnetic ground state. We have calculated the muon sites using the density functional theory calculation and present the results of internal field calculations at the muon stopping sites, which are in good agreement with the experimental observations. In the paramagnetic state, the INS data show three well defined CEF excitations near 8.0, 12.3, and 18.1 meV arising from the crystal electric field (CEF) split $J=4$ ground state of ${\mathrm{Pr}}^{3+}$. The CEF level scheme is deduced by analyzing the INS data by a model based on the CEF model.

FP Shell Effective Interactions and Nuclear Shell Structure of 44Sc

Abstract: Nuclear energy levels in 44Sc isotope, with fp shell model space occupation low levels fp-LS shell within shell model calculations had been investigated. The interactions has been used to calculate the nuclear energy levels which are fpd6, hw, fpy, with fp shell model space, d3f7cospn for 1d3/21f7/2 model space. The results are compared with each other and with available experimental data, its agreement with some results are clear. The used of model space interactions is the best fitted two body matrix elements in fp shell model space beside the good agreements in the reproduced values of energy levels scheme. The general estimation of the reproduced data are good especially below 3MeV. All inscriptions are given in diagrammatic notation, the wave vectors and analysis are modeled in the so called diagrammatic notation. The potential of oscillator is utilized to construct single particle vector, considering (_20^40)〖Ca〗_20 as a core for fp shell model space and (_16^32)S_(16 ) as an inert core for the model space d3f7. The OXFORD BEUNES AIRES SHELL MODEL CODE is utilized to accomplish the results for all tested nuclei.

Core-proton coupled nature of the 11/2+ state in 131 Sb probed by lifetime measurements

The structure of the state in 131Sb was investigated at the LOHENGRIN spectrometer of Institut Laue-Langevin via neutron-induced fission of 235U and lifetime measurements, yielding , at the edge of the sensitivity of the experimental method. This first result for the state half-life in neutron-rich Sb isotopes provides a quadrupole reduced transition probability to the ground state of W.u., very close to the in 130Sn. Realistic shell-model calculations reproduce well both the experimental level scheme of 131Sb and the value, indicting a dominant core-proton coupled configuration for the state.

Determination of drought tolerance of different strawberry genotypes.

Strawberry production future depends on productive, high quality and drought tolerant varieties. The goal of this study was to determine the most suitable variety by determining the yield and photosynthetic responses (net photosynthesis (Pn), stomatal conductance (gs), and transpiration rate (E)) of four strawberry genotypes with different characteristics (Rubygem, Festival; 33, and 59) at two different irrigation levels (IR50: water stress (WS), IR100: well-watered (WW)). It was also aimed to prepare the irrigation program by making use of the crop water stress index (CWSI). The trial was conducted at the Agronomic Research Area, University of Çukurova, Turkey during 2019-2020 experimental year. The trial was implemented as a 4 × 2 factorial scheme of genotypes and irrigation levels, in a split-plot design. Genotype Rubygem had the highest canopy temperature (Tc)-air temperature (Ta), whereas genotype 59 had the lowest, indicating that genotype 59 has better ability to thermoregulate leaf temperatures. Moreover, yield, Pn, and E were found to have a substantial negative relationship with Tc-Ta. WS reduced yield, Pn, gs, and E by 36%, 37%, 39%, and 43%, respectively, whereas it increased CWSI (22%) and irrigation water use efficiency (IWUE) (6%). Besides, the optimal time to measure leaf surface temperature of strawberries is around 1:00 pm and strawberry irrigation management might be maintained under the high tunnel in Mediterranean utilizing CWSI values between 0.49 and 0.63. Although genotypes had varying drought tolerance, the genotype 59 had the strongest yield and photosynthetic performances under both WW and WS conditions. Furthermore, 59 had highest IWUE and lowest CWSI in the WS conditions, proving to be the most drought tolerant genotype in this research.